There is a difference between expecting and needing. Everyone knew Maybin was a project, and anyone who expected a good rookie year was, frankly, ignorant. Maybin was drafted for long term development, and has rare speed and athleticism, which is why he was such a highly rated prospect.
Maybin may be a bust, or he might be the next Jason Taylor, but evaluating him now is idiotic. The kid might never be any good, but he has the talent to be a perennial sack leader.